I do that to people all the time- but more effectively. I go to my phones setting and turn it on airplane mode. I then proceed to text all my texts but obviously- they are stuck and won't send.

Then when people confront me about ignoring them, or being late- I say, no I texted you, then pull up my phone- acting all surprised to see all these texts stuck in my outbox. The best part is- the airplane mode symbol is extremely hard to notice, so I've never been caught. They always believe me, and it allows me to ignore people for the longest time.

if you're going to go through the trouble of writing the texts along with switching to airplane mode, why not just send the texts in the first place? If they're you're friends, it shouldn't be that big of a deal anyway.